1. Field of the Invention
This invention relates to differential pressure switch devices and more particularly to a new and improved differential pressure switch device being operable in response to both differential pressure and changes in temperature.
2. Description of the Prior Art
There have been known in the art a differential pressure switch device suited for use as a controlling device incorporated within, for example, an internal combustion engine control system for preventing the known undesired pollution gases from being exhausted from automotive vehicle engines. The capacity of the engine depends largely on temperatures of the engine. Accordingly, it is essential to control the engine system by the temperature of the engine in order to maximize the capacity of the engine.
However, since conventional differential pressure switch devices are operable in response to pressure regardless of temperature, it is necessary to employ a device operable in response to temperature to attain the above-noted purpose.